1. Technical Field
The present invention relates to a cleaning blade that includes an elastic member that comes into contact with a surface of a member to be cleaned so as to remove residual matter adhering on the surface of the member to be cleaned.
2. Description of the Related Art
In a typical electrophotographic image forming apparatus, residual toner adhering to the surface of an image carrier after transfer of a toner image onto a recording medium or an intermediate transfer body during an image forming process is removed by cleaning means.
A cleaning blade is used as the cleaning means due to its simple structure and good cleaning performance. A typical cleaning blade includes an elastic member composed of polyurethane rubber or the like and a supporting member. A base end of the elastic member is supported by the supporting member and a contact portion (tip ridge) of the elastic member is pressed against the image carrier surface so as to block and scrape off the residual toner on the image carrier surface to carry out removal.
However, as illustrated in FIG. 1A, a cleaning blade 62 composed of polyurethane rubber is pulled in a direction in which an image carrier 123 moves due to increased frictional force between the image carrier 123 and the cleaning blade 62 and a contact portion (tip ridge) 62c of the cleaning blade 62 is bent back as a result. Once cleaning is continued with the contact portion 62c of the cleaning blade 62 in a bent-back state, local friction X occurs in a tip surface 62a of the cleaning blade 62 at a position several micrometers distant from the contact portion 62c, as illustrated in FIG. 1B. If cleaning is further continued under such a condition, the local friction X is increased and, as illustrated in FIG. 1C, the contact portion 62c ultimately comes to have a missing part. Toner cannot be appropriately cleaned with a contact portion 62c missing, resulting in cleaning failure. In FIGS. 1A to 1C, reference numeral 62b denotes a lower surface of the cleaning blade.